Train and falcon puzzle????

Question

There are two train at station A and B.Distance in between them is 120 miles.They come towatds each other.Speed of 40 miles/hr each.As they strat to travel,a falcon starts flying,reaches at train B,and after that again comes to train A.This process continues until train crosses each other.Falcon's speed is 150 miles/hr.How much distance will be travelled by falcon before train crosses.

Answer 1

The question attempts to confuse you with the information that the falcon continuously lands and takes off from each train, but it's actually irrelevant when you need to calculate the distance it travels since it's flying full speed the whole time.

Since we know the velocity of the falcon we only need to find out for how long it's flying.

To calculate the time it takes two trains going at certain speeds to meet each other can be formulated like this:

Velocity of trainA * time (the unknown variable) + velocity of trainB * time = Distance between the two trains

40*x + 40*x = 120, 80x=120, x=1½

So it takes 1½ hour for the trains to meet each other, now multiply this  with the velocity of the falcon and you find the distance it's travelled:

150 mph * 1,5 h = 225 miles

Answer 2

To solve this problem, first we need to calculate time taken by both trains to cross over.

Distance between them --  120 km

individual Speed                 40 km each

Combined speed (Add two speeds since its direction is opposite)                           80 km/hr (40 + 40)  

Time taken                     =   Distance/Velocity

                                     = 120/80 = 1.5 hr

Total Falcon flying time is 1.5 hr

Its speed is 150 km/hr

Total distance travelled by falcon is  150 *1.5 = 225 km

                                    

Answer 3

225